The present invention relates to a document processing apparatus having a layout display control system therefor, and more particularly to a document processing apparatus having a layout display control system which, while the layouts of a plurality of pages of document data are being displayed in a plurality of respective layout display areas, can change a current page number and display an identification which distinguishes the layout display area corresponding to the current page number.
English word processors, for example, generally have a display for displaying a plurality of lines and also incorporate many functions to facilitate inputting and editing document data. Particularly, some word processors which have become available recently have a document layout display function for converting the arrangement of characters of document data into the arrangement of dots or line segments, and displaying the layout of each page of document data.
In a process for displaying the layout of document data, desired document data are displayed on a display, and a "layout" key is pressed to select a layout display mode and erase the displayed document data. Thereafter, a rectangular layout display area indicative of a printing area is displayed on the basis of format information relative to a printing format that has been inputted in advance, and then the layout of the current page of document data which was displayed on the display is disposed in the layout display area. At this time, the layout of a next page of document data or the layout of a previous page of document data is individually displayed when a "next page" key or a "previous page" key is pressed. For displaying the layouts of a plurality of document data, it has heretofore been necessary to display the layout of a first page of document data and thereafter press the "next page" key a plurality of times. Therefore, it has been inefficient to display the layouts of a number of document data.
The same inventors as this application have proposed a layout display control system for displaying a plurality of layout display areas on a display and displaying the layouts of a plurality of pages of document data including a current page in the respective layout display areas in a group.
The above proposed layout display control system has been frequently used in a word processor. In the word processor, however, the current page number cannot be changed while a layout is being displayed. To modify the layout of a page of document data other than the current page, the layout display mode is once canceled, and then the current page of document data which is indicated by the current page number is displayed on the display. Thereafter, a "next page" key or a "previous page" key is pushed to display a desired page of document data whose layout is to be modified. Such a process is however complex to be carried out.